This invention relates in general to conical structures and, more specifically, to high strength conical structures with a reinforcing rib construction.
In most metallic structures, such as buildings, large tanks, vehicles including automobiles, aircraft, etc., the exterior structure consists of a metal sheet skin mounted on a supporting frame comprising load carrying stringers. In some cases, the skin is stressed to increase the structure load carrying capacity. Such arrangements are complex and difficult to assembly in a manner providing truly uniform load carrying ability, but are often satisfactory for applications which do not require high strength in combination with low weight. Also, these structures generally do not efficiently distribute structural stresses under load, particularly impact loads.
In many applications, such as aerospace vehicles, a high strength-to-weight ratio is necessary in large, complex structures. Often structures such as aircraft fuselages, space launch vehicles, spacecraft, etc., are constructed from large, shaped, skin panels attached to elaborate stringer and reinforcement systems. These structures are complex, heavy, and do not possess uniform properties.
A high strength-to-weight ratio is especially difficult to achieve in structures which must have thin skin-plus-support thickness to permit effective use of the largest possible internal volume. This problem occurs in structures such as frusto-conical space launch vehicle inter-stage adapters, which may be filled with electronics and propulsion-related items, in conical pedestals or enclosures for military equipment, etc.
Thus, there is a continuing need for thin-walled conical structures of improved strength, high strength-to-weight ratios, and exceptional stress distribution under load.
It is, therefore, an object of this invention to provide a conical or frusto-conical structure having improved strength-to-weight characteristics.
Another object of this invention is to provide a thin-walled conical structure having improved stress distribution characteristics.